zguy36

No, those things will not cause dieseling. Describe your dieseling problem (how long it does it for, more about your engine) and maybe you can get some pointers on how to fix it.

I should have read this post a lot earlier, may have saved you some trouble. I ran into the exact same problems that you are having, which was a direct result of the FUEL INJECTORS. This may seem a bit odd, that injectors could cause this, but if you have low impedance injectors, they have some pretty nastly flyback voltages. The MS board was poorly designed in respect to the injector flyback, and this high voltage leaks into other parts of the MS causing some pretty bad glitches. Either put in a resistor pack for your injectors, swap out for high impedance injectors, or do some reading on the subject of the MS forum. There are a few board fixes that can be done (worked decent for me) that will aleviate your problems.

Deeper into the thread, you see where he cut apart two clutch disks and welded the parts together to make a 'performance' disk! SCARY

The guy didn't even use assembly lube on his bearings. No wonder the crank had "turning problems"

I tried making an air filter for a dirt bike when I was younger, just didn't work. I used a small bit of foam, similar to what you are doing on your intake. It took away half the power of the engine. Surface area is really where it's at. Unless the foam you plan on using is really open and really thin, it is going to restrict a lot. Better off just running a screen to catch the big stuff.

I dated a girl like that, could talk straight for extended periods of time, without me saying a word! took her for a ride in the Z though, that shut her up.

www.techlinecoatings.com the product was CBX, I bought it years ago. I don't think they sell it to the general public anymore, just shops. Could probably get one of the guys with a shop on here to do the purchase for you though. I actually have a set of coated pistons, that I was going to use during my last rebuild (got them ready, as I thought I had broken a ring land). I ended up using the ones that were already there, as they were still good! The coatings are easy to do, just follow the directions and bake em like cookies in your home oven. Open the windows though, as the oil residue that you can't clean out of the piston bottoms smokes up a storm!

I have had detonation/preignition (whichever it was) happen bad enough to break spark plugs, to the point the engine would barely run, or four different occasions with these same pistons. Yes, I was very stupid on my younger years with this motor, but sure did learn a lot. Still running the same pistons though. When one finally breaks, I am going to melt it down and make a lucky charm out of it. Not sure about the type of copper used, whatever comes in an SCE gasket.

This wasn't my first go around with building engines. This blew my mind, as well as the gasket! Before tearing the engine down, I rechecked the head bolt torque and it was right on. When I pulled the head, both the block and head were flat. It didn't blow right after a rebuild either, as it had 10,000 miles tearing it down. The engine wasn't torn down to add a ported head and that is when the gasket issues were found. Take it as you may, but the gasket failed before the pistons. The pistons (stock ones) have been ceramic coated with techline coatings CBX, which seems to be some pretty decent stuff. The only thing that I can figure is that it kept the pistons cool enough, that they could stand the detonation. I am guessing that the temps the pistons would normally run at high boost and detonation would be enough to soften the aluminum a bit, leading to piston failure before gasket failure. Looking at the gasket, the copper deformed away from the combustion chamber far enough for the o-ring to fall into the chamber. It moved maybe 3/16-1/4" making the fire ring egg shaped. It didn't blow far enough for combustion to be directly leaked into other chambers, or into water. This happened on three other holes as well, almost to the point that the o-ring slipped out. There was lots of evidence of detonation on the head, and the rod bearings were beat pretty badly as well, but the pistons faired pretty well. Well enough that they are still running in the same engine. On a side note, I annealed the rings on that last build by over-using the anti lag feature on the megasquirt. Sure is great to get the GT40 spooled up, but hell on EGTs. AFter this, there was enough blow-by that I thought I had broken a ring land. Pulling the engine apart again showed perfect pistons, just no tension left in the rings. Just some antedotal evidence, but seems as though the coating I used might be doing something.

Go with the steel gasket. i've blown an o-ringed copper gasket, but had no troubles with the mulit-layer steel. Yes, it saw some knocking and boost!

repost, but still good!

The problem that I a running into with a standard gasket, is the extra expansion that is happening due to stainless manifold construction. You can see where the manifold grows almost 3/8" between hot and cold. It is just tearing up the composite gaskets.

Hmm.... thirty five views and no interests..... think I will just hand build one!

I have been contemplating making a multi layer (stainless or mild) steel intake/exhaust gasket for my turbo l28. The composite gaskets that I have used are pretty crappy, especially when using a stainless header that has more expansion than the stock manifold. I know these gaskets work great for heads, but has anyone used them for intake/exhaust purposes? If anyone is interested, let me know. Having multiples of these cut on a water jet will greatly offset the setup fee.

I have mine set up with 1/8" clearance and have had no problems. There is not nearly as much torque to twist the engine in that direction on decel, so you should be all right with what you have. You would probably hear or feel it in the steering if there is a problem.

Might not be a problem with the turbo at all. Check to make sure you have a restrictor on your oil feed line (full oil pressure and flow will drown out your turbo). Also, check and make sure your return line is not plugged up, kinked, or in some way restricting flow. The return line needs to be at at least 3/4" diameter.

A difference in compression between cylinders will NOT cause this. You most likely have something loose under the hood, that is causing a ping like rattle at those engine speeds. What ever it is that is loose reaches a resonance at that RPM and is rattling away, sounding like detonation.

Did you do any calculations to see if you are getting flow separation on the trailing end of your divider on the inlet side? If that is the case, you are introducing a lot of turbulence into the rear section of the intercooler. I did notice that there were very few flow traces through the first few tubes. In any case, that is a ton better than the "as-purchased" design. Now, the real question is, why didn't you just buy a core and make your own stuff if you can do that good of work!

To use this pulley, you will have to use a belt from a 240 motor, not the 280 belt. This belt is a bunch narrower. Also, the pulley is about 15% smaller diameter, so you might even want to go with a tad shorter belt. A good parts store can look up the specs and get you one a bit shorter. As for the pulley, I haven't put any miles on it, as it was installed this winter. Come summer, I'll let ya know!

They would be derek, he's the one who did all of the work to make this manifold

He probably thought that you meant something different by not as strong, like as in they break easier.

Kevin, By raining on your parade, I wasn't trying to be negative, just truthful. What you are in a quest to achieve is something very difficult, if not impossible. Lets turn this conversation around and I'll try to be a little more helpful in what I am trying to explain. Lets go back to your 1/4 mile horsepower calculator. Using your equations on my setup, you get very different numbers. HP = ((Car Weight / (ET/5.825)^3) ==> ((2700/(13.8/5.825)^3)=203.1 HP = (mph / 234)^3 x Car Weight ==> (109/234)^3 x 2700 = 272.9 This equation uses empirical data that fit a set of numbers. Now looking at this setup, it seems as though my data would be an outlier. When this equation was made, it as based on a set of data that most likely included a set of drag race vehicles. Now you put my data in there, from a car with suspension and tires not set up for drag racing, and your numbers come out screwy. If your vehicle is properly set up for drag racing, then these equations will come out very close to yielding the same answer. The worse your vehicle is set up for racing, the worse the spread will be. Now, there are much better equations to calculate horsepower. Using simple kinematic equations you can very accurately calculate horsepower. Products such as g-tech use an accelerometer and these equations to do this. To accurately calculate horsepower without a dyno, use this equation d=vit+1/2at^2 Apply this equation to a small section of time when the vehicle is at a rate of around forty mph, which would have negligible wheel spin (for most vehicles) and little drag. This gives you a much more accurate answer. To make your equations more accurate, start holding some variables as constants. You seem to be on to something for normally aspirate engines. Hold this as a constant. Also, make some assumptions to reduce the variables. Assume that the exhaust is sufficiently large to not cause backpressure issues. Also, assume that the intake is sufficiently large to not cause breathing issues. Now, you have an equation that fits a large set of engines and weeds out the outliers. My point is that to extend this equation to turbocharge engines will be impossible. Since there are many good setups that are so different, you won't be able to map them with an equation. Keep to the NA engines and you might go somewhere.

Kevin, If you want any respect for your equations, then these equations need to be based on something more tangible than fudging numbers around from just a few sources. You mentioned that your equations are similar to horsepower calculators that use 1/4mile times. Those equations are built from the simple F=ma equation. You have not started from an equation that governs a law of physics, but instead taken two numbers and a couple variables and figured out a fudge factor to get your solution. I am not a naysayer, but someone who holds a degree in mechanical engineering and someone who understands that an equation should be based in something other than just a few small bits of empirical data. Equations based on empirical data are extremely vulnerable to error. I will reiterate why your equation will not work unless you take into account many many more factors. Cam profile: You can take two identical engines, both that have the exact same head flow rates but having different cam profiles. As you can imagine, these engines will not make the same power. Exhaust size: Again, two identical engines but with different exhausts. All of your input variables will be exactly the same, but again, power levels will be greatly different. Turbine size: Again, two identical engines but with different size exhaust turbines. Look at the different power levels that can be had. Take TimZ's engine with the GT42 turbo and replace it with the stock T3 turbo. Think you are going to get the same power level with the same boost pressure? No. Intake design: Again, two identical engines with two intakes. Both heads may flow the same, but depending on tuned runner lengths, you are going to get completely different power levels if one is tuned for low RPM vs. high RPM. Fuel type: Depending on the fuel being used, you advance your timing curves and increase power levels, all other factors being the same. I have only listed here a few variables of which can have an effect of 50+ horsepower differences. I tried very hard to not rain on your parade last time, but I think it is time that some rain starts to fall. Plainly put, there are so many variables involved with modeling internal combustion engines, that it is mathematically impossible to come up with a catch all equation. What you have created is something that fits for a small set, with very few variables. Yes it seems to work, but you can't really say that it holds much merit. You may say that it can be done, since you can purchase programs such as desktop dyno that do exactly what you are trying to do. Well, these programs use a similar approach as you, but pull from a data base of thousands versus a database of a handful. And just the same with these programs as your equation, if you change the variables out of the range of what is mapped in the database, then your result is useless.

I build a twin scroll valve as well and had the same luck that Thaggard had. I didn't make any noticeable difference and I ended up scrapping the idea. Yours might work, who knows. I can give you some advice on how to actuate this thing though. I ended up using a diaphram solenoid from an RX7 (used for the same purpose on this car). If you adjust the spring rates on your wastegate and on your twin scroll actuator, you can get the twin scroll actuator to be fully open just before the wastegate starts to open. Control pressure to both lines via your boost controller, and the whole thing will function flawlessly.

Hmmm... which numbers were fudged? All of them!! Your method of finding an equation doesn't start from any theory, from any laws of physics or thermodynamics. You have taken a start number and an end number and come up with a simple equation that takes you from point A to point B for a small set of numbers. Apply this to a set that is different from your initial set and your equation doesn't work. To sit and dwell on the fact that these numbers seemed to have worked out for such a small set, and an equation based on no theory is a bit naive. Do some searching on amazon and find some automotive engineering books. It won't take you long digging into these to learn a few more tools to play with.